Minimal Thermal Requirements for Development and Activity of Stored Product and Food Industry Pests (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera and Blattodea): A Review

Low temperatures play an important role in arthropods because they affect both the individual and population development of all physiological and behavioural activities. Manipulation with low temperatures is a primary nonchemical pest control method. For stored product and food industry practitioners, a knowledge of pest thermal requirements, in particular threshold temperatures at which development and other activities of a particular pest species cease, is of crucial importance. This review presents summary data regarding the lower temperature thresholds of 121 species of stored product and food industry pests from six arthropod taxa (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera, and Blattodea). In particular, this review collected and summarized information regarding the lower development thresholds, lower population thresholds, lower acoustic or respiratory thresholds, lower walking and flying thresholds and lower trap capture thresholds for flying and walking arthropods. The average lower development threshold (LDT) differed among orders: the lowest was reported for Acari (6.8 °C) and Diptera (8.1 °C), followed by Lepidoptera (11.3 °C) and Psocoptera (13.8 °C), and the highest was reported for Coleoptera (14 °C) and Blattodea (15 °C). An exclusion-function was established showing the percentage of pest species (n = 112) that were developmentally suppressed (excluded) due to temperatures reaching the LDT in the range of decreasing temperatures from 25 °C to 0 °C. We scaled various temperature thresholds from the lowest to highest temperature as follows: the walking threshold, the trap capture threshold for walking insects, the lower development threshold, lower population threshold, lower flying threshold and the lower trap capture threshold for flying pests. Important pest species were identified for which information regarding the lower temperature threshold is missing, or for which the information is too variable and should be refined in future research.

Potential of astigmatid mites (Acari: Astigmatina) as prey for rearing edaphic predatory mites of the families Laelapidae and Rhodacaridae (Acari: Mesostigmata)

Laelapidae and Rhodacaridae are important families of edaphic predatory mites and species of these families have been considered for use in biological control programs of soil pests. Mites of Cohort Astigmatina (Acari: Sarcoptiformes) have been largely used as factitious prey in the mass rearing of various edaphic or plant-inhabiting predatory mites. Stratiolaelaps scimitus (Womersley) (Mesostigmata: Laelapidae) (widely commercialized for the control of fungus gnats and thrips) and Protogamasellopsis zaheri Abo-Shnaf, Castilho and Moraes (Mesostigmata: Rhodacaridae) (not available commercially but promising for the control of thrips and nematodes) are known to be reared on Tyrophagus putrescentiae (Schrank) (Astigmatina: Acaridae), but the possibility to find a perhaps more efficient prey has not been evaluated. The objective of this paper was to evaluate different astigmatid species as prey for these predators. S. scimitus and P. zaheri oviposited on all evaluated astigmatids and the acarid mites T. putrescentiae and Aleuroglyphus ovatus (Tropeau) were the most suitable prey; to confirm the effect of prey on oviposition rates, pregnant females of the predators were kept under starvation conditions and oviposition was negligible or null. Survivorship was always higher than 78 % and was not influenced by prey species or starvation.

Potential of Five Brazilian Populations of Phytoseiidae (Acari) for the Biological Control of Bemisia tabaci (Insecta: Hemiptera)

Biotype B of the whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), causes considerable losses to growers worldwide. Phytoseiid mites have been successfully used for the control of this pest in several countries. The Brazilian phytoseiid fauna is very diverse and potentially useful for this purpose. The aim of this study was to evaluate five Brazilian populations of phytoseiids as candidates for the control of the whitefly, a serious pest of different crops worldwide. Evaluated species were Amblydromalus limonicus (Garman & McGregor), Amblyseius herbicolus (Chant), Amblyseius largoensis (Muma), Amblyseius tamatavensis (Blommers), and Neoseiulus tunus (De Leon), which are found naturally in Brazil and elsewhere. The work was conducted at 28±1°C, 75±10% relative humidity, and a photoperiod of 12:12 (L:D) h. All evaluated phytoseiids preyed on eggs of B. tabaci, with the highest levels of predation recorded for Am. herbicolus and N. tunus, and highest level of oviposition recorded for Am. tamatavensis. The results show the Brazilian populations of those three species to be promising as control agents of B. tabaci. Aleuroglyphus ovatus (Troupeau) (Acari: Acaridae) was found to be a suitable prey for the mass production of those predators. Complementary studies are considered justified, given the positive results of this study.

Complete mitochondrial genome of Aleuroglyphus ovatus (Acari: Acaridae)

In this study, the complete mitochondrial genome (mitogenome) sequence of Aleuroglyphus ovatus (Acarinae: Aleuroglyphus) was determined by long PCR and primer walking methods. The complete mitochondrial genome is 14,305 bp in length and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes as well as a displacement loop (D-loop). The overall base composition of the genome is A (23.61%), T (44.60%), C (13.03%) and G (18.76%) respectively. Stop codon was missed for the CYTB gene and the gene overlaps were suggested between ten pairs of the contiguous genes in A. ovatus. The mitogenome would contribute to resolving phylogenetic position and interrelationships of Aleuroglyphus.