Responses of the oriental fruit fly, Bactrocera dorsalis (Hendel), third instar larvae to desiccation and immersion were examined at 25°C in the laboratory condition. Third instar larvae desiccated in dry soils (0% field capacity) did not survive beyond 12 h, nor submerged under water beyond 3.5 d. The time to 50%, 90%, and 99% mortality (LT₅₀, LT₉₀, and LT₉₉) were 5.67, 8.60, and 10.99 h respectively in desiccation condition, and 1.81, 2.49, and 3.06 d in immersion test. The average eclosion time of survived flies was not significantly affected by the desiccation time, while that increased linearly with increasing immersion time. Cumulative weight loss of larvae increased curvilinearly with desiccation time, and the rate of weight loss was greatest during the first 2 h. The relationship between the mortality and the percentage of cumulative weight loss was described by Probit model in desiccation. It was estimated that when the percentage of cumulative weight loss was 29.1%, 36.7%, and 43.0% respectively, the mortality rates was 50%, 90%, and 99% correspondingly.

Filth flies play a major role in the transmission of microbial organisms that cause disease in animals and humans. A procedure was developed using filter paper to collect filth fly fecal/regurgitation droplets at dairies and turkey production facilities that could be used to detect pathogen DNA carried by filth flies. Weekly fly fecal/regurgitation droplets were collected on 11 cm diameter filter paper that was either tacked to beams or stapled to 30 cm wooden stakes. Molecular diagnostics using polymerase chain reaction (PCR) procedures detected the presence of Escherichia coli H7, Campylobacter sp., and Cochlosoma anatis DNA in fecal/regurgitation droplets deposited by filth flies at two dairy and one turkey farm in Arkansas. This procedure provided a rapid and effective method to monitor pathogen presence in filth fly populations.

The susceptibility of adult sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), to five local Syrian isolates of Heterorhabditis bacteriophora, Steinernema riobravae Texas, S. carpocapsae C3B, and H. bacteriophora 8-14 strains was evaluated under laboratory conditions. Concentrations of 50, 100, 200, and 400 nematodes per adult were bioassayed; for each nematode concentration, four groups of five sunn pests in Petri dishes were used and mortality was recorded daily for five d. The mortality induced by nematodes increased, typically with increasing numbers of nematodes per adult and ranged from 30 to 90%. Overall, Heterorhabditis bacteriophora Musherphe strain produced the lowest mortality and Steinernema riobravae Texas strain produced the highest mortality. The LC₅₀ values of H. bacteriophora Musherphe, S. carpocapsae C3B, and S. riobrave Texas were 107.1, 66.6, and 65.3 nematodes per adult sunn pest, respectively. LT₅₀ values ranged from 3.6 to 7.2 d for H. bacteriophora Tabeh-gazira and H. bacteriophora Musherphe strains at 50 nematodes per sunn pest, from 2.9 to 5.1 d for H. bacteriophora Tabeh-gazira and H. bacteriophora Ariha strains at 100 nematodes per sunn pest, from 2.2 to 4.3 d for S. carpocapsae C3B and H. bacteriophora Ariha strains at 200 nematodes per sunn pest, and from 2.0 to 4.3 d for S. riobrave Texas and H. bacteriophora Musherphe strains at 400 nematodes per sunn pest, respectively. Our results suggest that H. bacteriophora Tabeh-gazira, H. bacteriophora El Ratla-1, H. bacteriophora El Ratla-2, H. bacteriophora 8-14, S. carpocapsae C3B, and S. riobrave Texas strains have potential as biocontrol agents against the sunn pest.

Bradysia odoriphaga Yang and Zhang is the most serious pest of Chinese chive, Allium tuberosum Rottle ex Spreng. (Liliaceae) in North China. Pesticide residues in this vegetable are very high following excessive use of organophosphorate insecticides. Because there have been no reports on the sex pheromones of B. odoriphaga, sex pheromone and mating behavior of B. odoriphaga were investigated as a possibility of developing semiochemical-based monitoring and control of this pest. In laboratory bioassays, live B. odoriphaga virgin females stimulated 78% of males to vibrate their wings and 67% of males to attempt to mate. Methylene dichloride washes of female whole bodies and excised ovipositors also attracted males. In field test, many B. odoriphaga males were attracted to the traps containing live B. odoriphaga virgin females or methylene dichloride washes of female whole bodies. Most flies mated only once, while a few mated as many as six times. After mating, females were still attractive to males. Flies' sexual behavior showed a daily rhythm. The higher mating activity was from 2200 to 0600 h and the lower from 1200 to 1800 h. These results indicate the presence of a female sex pheromone in B. odoriphaga with the ovipostor as the most likely source of pheromone production. It is possible to collect the maximum amount of sex pheromone between 2200 and 0600 h. There is the possibility that this sex pheromone may be used to monitor and control of B. odoriphaga in the future.

A survey of hymenopteran and dipteran parasitoids of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) larvae was conducted to determine their occurrence and parasitism rates in Western Chiapas, Mexico. 1247 FAW larvae were collected from whorl-stage corn cornfields in 21 locations in the region called “La Frailesca” in Chiapas, Mexico during the summer of 2002; 251 larvae produced parasitoids for an overall parasitism rate of 20.1%. Five braconids were recovered from FAW larvae, Rogas vaughani Muesebeck, R. laphygmae Viereck, Chelonus insularis Cresson, C. cautus Cresson, and Glyptapanteles militaris Walsh. Two ichneumonids, Neotheronia sp., and Ophion flavidus Brulle, and one eulophid, Euplectrus plathypenae Howard were recovered. Dipteran parasitoids were also recovered from last instars. These were the tachinids Archytas marmoratus Towsend, Lespesia archippivora Riley, Archytas sp., and Winthemia sp. Megaselia scalaris Low was a unique phorid recovered. Dipteran parasitoids produced a parasitism rate of 6.3%, and were mostly recovered from 5^th and 6^th FAW instars. Most of the parasitoid species were recovered from FAW larvae that were collected from corn plants in the V3 growth stage. In this survey, O. flavidus, E. plathypenae, Chelonus spp., and species of Rogas (Syn: Aleiodes) were the most frequently recovered species in “La Frailesca”.

Entomopathogenic fungi (e.f.) are important agents of biological control of insects. Two aspects, among others, are important for the use of e.f. against insect pests: the logistics of e.f. strain acquisition, and the activity of individual strains against multiple insects. Soil is the natural reservoir for many e.f., but only few strains used against insect pests originate from soil; most have been isolated from insects. Also, there are few reports that simultaneously compare the activity of individual strains of e.f. (of insect or soil origin) against more than one insect species. This is important for the deployment of e.f. in agroecosystems, where simultaneous control of several insect pests is very often desirable. In this work we determined and compared the simultaneous activity of local strains of e.f. (isolated from soil or insects at Saltillo, Mexico) against important regional pests: fall armyworm, Spodoptera frugiperda, greenhouse whitefly, Trialeurodes vaporariorum, and potato psyllid, Bactericera cockerelli. Against all three insects, one Beauveria bassiana strain from soil was as active as or more active than other B. bassiana and Metarhizium anisopliae strains from insect or soil origin. In some localities, native individual strains of e.f. from soil might have good activity against multiple local insect pests. We recommend the isolation and testing of local soil strains of e.f. for use in local biocontrol projects.