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The predators Macrolophus basicornis (Stal), Engytatus varians (Distant) and Campyloneuropsis infumatus (Carvalho) consume large numbers of tomato pests such as Bemisia tabaci (Gennadius) and Tuta absoluta (Meyrick). However, they are zoophytophagous and feed on plant parts as well. We evaluated the type and effect of injury caused by nymphs and adults of these mirids on tomato seedlings and fruit in the absence of prey. For each mirid species, seedlings were exposed to groups of 20 nymphs or adults for 72 h, and fruits were exposed for 48 h to groups of four nymphs or adults. Type and the number of injury on stems, petioles and leaflets of tomato seedlings and fruits were recorded after removal of insects. Nymphs and adults of these mirids caused necrotic rings on the leaflets, but no injury was observed on stem and petioles. The necrotic rings on leaflets consisted of blemishes, characterized by feeding punctures surrounded by a yellowish, bleached area. The number of necrotic rings did not exceed one per individual mirid and seedlings developed normally. Nymphs also caused feeding punctures on tomato fruit, but in even lower numbers than on leaflets. Two weeks after the start of the experiment the tomato fruit still looked fresh and feeding punctures had disappeared. Adults did not cause any injury to tomato fruit. The results indicate that nymphs and adults of these zoophytophagous mirids cause little injury to tomato seedlings and fruit, even when present in high densities and in the absence of prey, making them interesting candidates for biological control.

Plants release a variety of volatile organic compounds that play multiple roles in the interactions with other plants and animals. Natural enemies of plant-feeding insects use these volatiles as cues to find their prey or host. Here, we report differences between the volatile blends of tomato plants infested with the whitefly Bemisia tabaci or the tomato borer Tuta absoluta. We compared the volatile emission of: (1) clean tomato plants; (2) tomato plants infested with T. absoluta larvae; and (3) tomato plants infested with B. tabaci adults, nymphs, and eggs. A total of 80 volatiles were recorded of which 10 occurred consistently only in the headspace of T. absoluta-infested plants. Many of the compounds detected in the headspace of the two herbivory treatments were emitted at different rates. Plants damaged by T. absoluta emitted at least 10 times higher levels of many compounds compared to plants damaged by B. tabaci and intact plants. The multivariate separation of T. absoluta-infested plants from those infested with B. tabaci was due largely to the chorismate-derived compounds as well as volatile metabolites of C 18 -fatty acids and branched chain amino acids that had higher emission rates from T. absoluta-infested plants, whereas the cyclic sesquiterpenes α- and β-copaene, valencene, and aristolochene were emitted at significantly higher levels from B. tabaci-infested plants. Our findings imply that feeding by T. absoluta and B. tabaci induced emission of volatile blends that differ quantitatively and qualitatively, providing a chemical basis for the recently documented behavioral discrimination by two generalist predatory mirid species, natural enemies of T. absoluta and B. tabaci employed in biological control.

Tuta absoluta (Meyrick) has quickly developed into a significant tomato pest worldwide. While the recently found mirid predators Macrolophus basicornis (Stal), Engytatus varians (Distant) and Campyloneuropsis infumatus (Carvalho) of this pest are able to establish and reproduce on tomato, biological knowledge of these mirids is still limited. Here we describe the functional response of the three mirid predators of the tomato pest T. absoluta when offered a range of prey densities (four, eight, 16, 32, 64, 128 and 256 eggs) during a 24 h period inside cylindrical plastic cages in the laboratory. Engytatus varians and M. basicornis showed a type III functional response, whereas C. infumatus showed a type II functional response. At the highest prey densities, C. infumatus consumed an average of 51.0 eggs, E. varians 91.1 eggs, and M. basicornis 100.8 eggs. Taking all information into account that we have collected of these three Neotropical mirid species, we predict that M. basicornis might be the best candidate for control of the tomato borer in Brazil: it has the highest fecundity, the largest maximum predation capacity, and it reacts in a density-dependent way to the widest prey range., Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Leafminers (Diptera: Agromyzidae) are pests of various crops, mainly in greenhouses, and have Diglyphus spp. as important leafminer larval parasitoids. Until recently, only Diglyphus insularis (Gahan) had been reported in Brazil. In here we report the first records of Diglyphus begini (Ashmead), D. intermedius (Girault) and D. isaea (Walker) in Brazil. These parasitoids were found parasitizing leafminer larvae on cultivated and spontaneous plants in some areas of Minas Gerais state, Brazil.

Interspecific competition between parasitoid larvae may influence the size, structure, and stability of the population, leading to a reduction in total parasitism and thus restricting the pest control. Aphidius ervi (Haliday) and Praon volucre (Haliday) are endoparasitoids that possess a wide host range and present considerable potential for the biological control of the aphid Macrosiphum euphorbiae (Thomas). The larval competition between A. ervi and P. volucre, and the possible intrinsic competitive superiority of one of the parasitoids in M. euphorbiae, have been studied. In single parasitism experiments, mated parasitoid females (n=10) were maintained individually in contact with M. euphorbiae hosts (n=30) inside petri dishes containing lettuce leaf discs and maintained in environmental chamber at 22 ± 1°C, 70 ± 10% RH, and 12-h photophase. The multiple parasitism experiments consisted of exposing single parasitized aphids (n=120) to the second parasitoid species. Two oviposition events were performed with a 4-h interval between them, namely the following: sequence A (oviposition by A. ervi, followed by P. volucre) and sequence B (oviposition by P. volucre, followed by A. ervi). Oviposition sequence A generated 24 A. ervi and 55 P. volucre adults, whereas oviposition sequence B generated 23 and 49 adults. P. volucre is an intrinsically superior competitor compared with A. ervi, and the use of the two species simultaneously may result in competitive exclusion and influence the stability of the parasitoid population.

The suitability of Macrosiphum euphorbiae (Thomas), Aulacorthum solani (Kaltenbach) and Acyrthosiphon kondoi Shinji (Hemiptera: Aphididae) as hosts for the aphid parasitoid Aphidius ervi Haliday was evaluated by assessing host size, host preference, and host quality. Tests were carried out in an environmental chamber at 22±1ºC, 70±10% RH and 12h photophase. Replicates (11) consisted of one 24h-old mated female of A. ervi without a previous oviposition experience. Female was released into a Petri dish (5 cm) with 20 2nd and 3rd instars of one of each aphid species tested on a leaf disc of the host plant onto a 1% water-agar layer. Parasitoid emergency was lower in A. kondoi (78.7%) compared to M. euphorbiae (92.2%) and A. solani (91.7%). Acyrthosiphon kondoi (0.36 mm) was the smallest host. The parasitoid showed preference (74.0% parasitism) for M. euphorbiae, the largest host (hind tibia length=0.73 mm), which in turn yielded larger A. ervi females (0.75 mm).

Lysiphlebus testaceipes (Cresson) has a broad aphid host range; however the quality of these preys may interfere in its biological feature. This study aimed to evaluate the quality of three Macrosiphini, Brevicoryne brassicae (L.), Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer), and three Aphidini Schizaphis graminum (Rondani) Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover as hosts to L. testaceipes and to determine the relation possible of host preference, of size and quality of the host. The tests were carried out in climatic chamber at 25 +/- 1 degrees C, RH 70 +/- 10% and 12h photophase. The parasitoid did not oviposite in B. brassicae and L. erysimi, while the other species were nutritionally suitable to the parasitoid. L. testaceipes showed preference for aphids from tribe Aphidini and these hosts presented better quality to the parasitoid when compared to Macrosiphini. Interactions among size, preference and quality between the Aphidini were found. L testaceipes showed preference (parasitism rate 76.7%) for R. maidis, the bigger host (hind tibia with 0.281 mm). This host provided bigger size (hind tibia with 0.49 mm) and higher emergence rate (95.6%) to the parasitoid when compared to A. gossypii (parasitism rate of 55.7%). Also the smaller host A. gossypii (0.266 mm) provided smaller size hind tibia (0.45 mm) and higher mortality of the parasitoid (emergence rate 72.1%). However, the development time was shorter and the longevity was higher in A. gossypii (6.3 and 5.4 days, respectively) when compared to the host R. maidis (6.7 and 3.8 days, respectively), and not been related to host size.

The intrinsic rate of increase of a parasitoid related to its hosts play an important role in biological control programs. In this work, fertility of the parasitoid Aphidius colemani Viereck was evaluated on Aphis gossypii Glover by means of a fertility life table. To determine the immature mortality, the development time and the sex ratio, 12 mated females of A. colemani (24h old), and 240 nymphs of A. gossypii (3 days old) were used. To evaluate fertility 15 mated females (24h old) were used. For each parasitoid female, 300 nymphs were offered in the 1st day, 250 nymphs in the 2nd day, 200 nymphs in the 3rd day, 150 nymphs in the 4th day, 100 nymphs in the 5th day and 50 nymphs in the other days. Immature mortality of A. colemani was 22.1%, development time of males and females were 12.0 and 11.8 days, respectively, and sex ratio was 0.6. The females of A. colemani laid 420 eggs and had longevity of 5.9 days. The net reproduction rate (R(o)) was 194.81 females and the intrinsic rate of increase (r(m)) was 0.384 females/females/day. The finite rate of increase (lambda) was 1.48 females/day, the mean length of a generation (T) was 13.74 days and the time to duplication the population (TD) was 12.60 days. The parasitoid A. colemani had a great potential of population growth on A. gossypii as a host and could be an effective biological control agent of this aphid.

Aphidius colemani Viereck is among the main natural enemies used for biological control of Aphis gossypii Glover. The objective of the present study was to evaluate the development of A. colemani and the alterations caused by the parasitism in the host A. gossypii in different temperatures and to estimate the thermal requirements of the parasitoid. The experiments were carried out in controlled environmental chambers at 16, 19, 22, 25, 28 and 31 +/- 1 degrees C, 70 +/- 10% RH, and 12h photophase. Second-instar nymphs of A. gossypii were parasitized once and kept individually in glass tubes (2.5 cm x 8.5 cm), containing leaf disc of cucumber (2 cm) and 1% water/agar solution. The development time of A. colemani, from oviposition to mummies (11.9, 9.8, 7.7, 6.4 and 6.4 days) and from oviposition to adult (19.4, 16.2, 12.6, 10.5 and 10.7 days) decreased with the increase of the temperature from 16 degrees C to 25 degrees C. The rates of mummies and the emergence of the parasitoid, and its longevity also decreased with the increase of the temperature. Mummies were not produced at 31 degrees C. The lower temperature threshold of A. colemani was 5.94 degrees C and its thermal constant was 200 degrees-day. The alterations caused by the parasitoid in the A. gossypii host were minimized at 31 degrees C, where 98% of the host did not show symptoms of parasitism and produced nymphs. The temperature of 22 degrees C was optimal for the development time of A. colemani.

Several species of Orius Wolff are used in biological control of thrips in protected cultivations in temperate regions, but some of them show reproductive diapause, compromising the efficiency of these agents of biological control. There are no reports on the biology of the neotropical species Orius thyestes Herring under different environmental conditions. The purpose of this work was to investigate the influence of photoperiod on reproduction and longevity of this predator. Nymphs were kept in petri dishes in climatic chambers at 28+/-1 degree C, 70+/-10% RH and under the photoperiods of 12L:12D, 11L:13D, 10 L:14D e 09L:15D. The mating adults were kept in petri dishes with Bidens pilosa L. Asteraceae inflorescences as oviposition substracts and eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) as food. The pre-oviposition and oviposition periods, fecundity and longevity were evaluated and O. thyestes did not show reprodutive diapause in all photoperiod conditions established. The mean number of eggs obtained per female decreased with the reduction of the photophase, with a difference (P < 0.05) between the values obtained in 12h and 9h of photophase. Longevity of females and males under 9h photophase was shorter (P < 0.05) than in all other photoperiods tested. The knowledge of the biology of the natural enemy under different conditions allows to optimise the mass rearing and to predict the performance of the predator in different photoperiods which may occur along the year and in greenhouses.

The parasitoids Lysiphlebus testaceipes (Cresson) and Aphidius colemani Viereck play an important role on the regulation of aphid populations on chrysanthemum grown in greenhouses. This study evaluated the interaction of biological control and plant resistance by the development and the parasitism of L. testaceipes and A. colemani on Aphis gossypii Glover. The aphid host was kept on commercial cultivars of chrysanthemum susceptible Yellow Snowdon (YS) and resistant White Reagan (WR). The experiment was carried out in climatic chamber at 22 +/- 1 masculineC, 70 +/- 10% RH, and photophase 12h. Nymphs of 2nd and 3rd instars of A. gossypii attacked only once by the parasitoids were used in the experiment. The development time was 15.0 and 12.9 days for L. testaceipes and 17.0 and 16.3 days for A. colemani kept on A gossypii on cvs. YS and WR, respectively. The parasitoid L. testaceipes showed greater parasitism rate (68.4%) on A. gossypii on cv. YS than on WR (50%), and for A. colemani was not found significative difference on parasitism (46.8 and 35% to YS and WR, respectively). The emergence rates of L. testaceipes and A. colemani were 91.6% and 85.3% on A gossypii reared on YS, and 78.1% and 100% on WR, respectively. The longevity of A colemani and the parasitism rate of L. testaceipes were affected in a negative way by the cv. WR. The results indicated a positive interaction of biological control with parasitoids and the resistant cv. WR on A. gossypii control in protected cultivation.