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Se evaluaron dos acaricidas por su efectividad para controlar las poblaciones de la garrapata sureña Boophilus microplus en ganado lechero en Santa Cruz, Islas Virgenes Americanas. Se asperjaron dos concentraciones diferentes de una formulación microencapsulada (ME) de permetrína (0.05 y 0.10% ia) y una concentración de coumaphos concentrado emulsificable (0,117% ia) sobre novillas Holstein que presentaban una infestación natural de garrapatas. La actividad residual del coumaphos y la permetrina ME (0.05% ia) fue por lo menos de cuatro días y la de permetrina ME (0.10% ia) fue de por lo menos siete días. El largo del periodo residual de la permetrina ME sobre el Boophilus microplus no aumentó en comparación con experimentos de campo con otras formulaciones de permetrinas. El porcentaje de control para los tres tratamientos desde los días 4 al 21 fue: permetrina ME (0.05% ia), 96%; permetrina ME (0,10% ia), 97%; coumaphos, 98.3%. Las diferencias entre las medias de los diferentes tratamientos no fueron significativas (F= 2.21; g.l. = 2,17, P> 0.10). Esta investigación confirma que la permetrina es una alternativa para el control de B. microplus en poblaciones de ganado.

The ovipositional biology and egg development of the tropical horse tick, Dermacentor (Anocentor) nitens (Neumann), was observed at four temperatures (20, 25, 30, and 35 degrees C) and relative humidities (40, 61, 75, and 91% RH). Relative humidity had little effect on length of preoviposition and oviposition periods. With increased rearing temperatures, there was a decrease in both preoviposition and oviposition periods. Oviposition rate increased with temperature and was not affected by relative humidity. Instantaneous rates of oviposition were calculated for each temperature by fitting the data to the logistic growth function. High percentage egg hatch was observed in low saturation deficit environments, and decreased when saturation deficit was increased.

Experiments were conducted to determine the effects of feeding larvae of the darkling beetle (lesser mealworm), Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) to broiler chicks on chick growth. Chicks readily fed on the larvae and exhibited reduced growth in the absence of other feed. Chicks 3 to 8 d old restricted to a diet of only larvae consumed 1,552 +/- 172 (mean +/- SD) larvae per chick per day and their body weights were significantly less (mean = 84 g) at the end of the 6 d than for chicks on starter feed during the same time. After return to starter feed for 8 d after feeding on larvae for 6 d, the chicks did not compensate for the reduced weight and their body weights were significantly less (mean = 170 g) than for chicks on starter feed for the 14 d. Chicks from age 2 through 9 d were given a choice between broiler starter feed and darkling beetle larvae. The numbers (mean +/- SD) of larvae consumed per chick per day were: 389 +/- 18, 631 +/- 14, 496 +/- 20, and 287 +/- 33, for Days 2 to 3, 4 to 5, 6 to 7, and 8 to 9, respectively. The body weight of chicks feeding on starter feed and larvae was significantly greater than the weight of chicks consuming feed only. In the presence of larvae, the mean feed consumption per chick was less than for chicks provided with only starter feed. The beetle larvae were 68% crude protein and 21% fat (DM basis) and had higher amounts of 18 amino acids than the starter feed.

Experiments were conducted to determine the effects of feeding larvae of the darkling beetle (lesser mealworm), Alphitobius diaperinus (Panzer) [Coleoptera:Tenebrionidae], to turkey poults on poult growth and of beak trimming on poult feeding on the larvae. Young turkey poults readily fed on the larvae and exhibited reduced growth in the absence of other feed. Poults 3 to 5 d old restricted to a diet of only larvae consumed 259 +/- 99 (+/- SD) larvae per poult per day and their body weights were significantly lower (mean = 30 g) at the end of the 3 d than for poults on starter feed during the same time. After return to starter feed for 16 d after feeding on larvae for 3 d, the poults did not compensate for the weight loss although weight gains were normal. Poults from 2 through 10 d of age were given a choice between starter turkey feed and darkling beetle larvae. The numbers of larvae consumed per poult per day were: 174 +/- 8 for Days 2 to 4, 221 +/- 3 for Days 5 to 7, and 189 +/- 80 for Days 8 to 10. There was no significant difference between the body weight of poults feeding on larvae and starter feed compared with that of poults consuming feed only. In the presence of larvae, the mean feed consumption per poult was lower than for poults provided with only starter feed. The beetle larvae were 68% crude protein and 21% fat (DM basis) and had higher amounts of 18 amino acids than the starter feed. Poults that were beak trimmed consumed only about one-third as many larvae as poults with intact beaks. Poults (1 to 3 d old) with intact beaks consumed 169 +/- 20 larvae per poult per day; poults with trimmed beaks consumed 58 +/- 23 larvae per poult per day.

Three tests were conducted in Montgomery Co, VA, in Jul, Aug, and Sep with insecticides in dust bags applied to mixed breed beef cattle to measure control of face and horn flies. In Test A 2 dust bags containing 12 lb each of 1% Co-Ral (Coumaphos) were suspended 30 in above the ground at 2 entrances to a mineral box on Jul 24. Thirty mixed breed heifers were in the treated herd.

‘Northrup King PX79’ field corn was sod-planted on May 15, on the VPISSU Agronomy Farm, Montgomery Co, VA. The land had been in sod for several years. At the time of planting the water content of the soil was 26.25% and the pH was 6.3. A tank-mix of Paraquat, Atrazine, and Dual was applied prior to planting. Three rates of BAS 263 11 I (3.6, 2.4, 1.2 oz ai/1000 ft) were applied on May 18 with a Gandy granular applicator using a 7-in band at the height of 5 in. Treatments were replicated 4 times on completely randomized plots measuring 12 ft x 5(1 ft (each plot was 4 rows wide - 36 in rows). White grub populations were estimated before planting by taking 4-in core samples over the entire treat area. The grub population averaged 12 grubs per 4-in core. Control was evaluated on Jul 23. Ten cores (4 in), consisting of 1 corn root system and the associated soil, were taken from each plot (40 cores per treatment) to determine the average number of white grubs per core.