Reproductive parameters of the parthenogenetic psocid Lepinotus reticulatus (Psocoptera: Trogiidae) at constant temperatures

Psocoptera (Psocodea) in Spice and Medicinal Dehydrated Plants Sold in Bulk in a Big Metropolis in Brazil

In Brazil, the production of dried herbs and condiments is on a smaller scale than that of its other agricultural sectors; however, it has been growing and attracting new producers, driven by the stimulus to provide healthy and gourmet foods. Insects in the order Psocoptera may cause loss of quality in such dried foods, and because of their small size, these insects can be easily transported by commerce. No information is available on how these insects may be entering Brazil via the importation of dehydrated products or how they may be exported with the increase of Brazilian dried food production. To examine these issues, 10 sites offering foods sold in bulk within the city of São Paulo, Brazil, were chosen. At each food site, the same 20 species of aromatic spice and medicinal dehydrated plants were purchased. In the laboratory, they were analyzed for the presence of insects immediately after acquisition. After removal of nymphal and adult psocopterans, the plants were kept in vials under environmental conditions to be investigated 40 days later. Psocopterans were found in 12 of the 20 dehydrated plant species. Eleven psocopteran species were recorded, including six species of unidentified Liposcelis. Liposcelis bostrychophila (Badonnel) was found in all samples with the presence of insects. The other frequent species were Liposcelis entomophila (Enderlein) and Lepinotus reticulatus (Enderlein). Lepinotus reticulatus constitutes the first record in Brazil. In total, 1,021 insects were recorded in the evaluation right after purchase, and this number grew to 3,734 individuals recovered 40 days later under laboratory conditions. The data show that in a relatively short period of storage, a population increase occurs that may cause loss of product quality and a decrease in organoleptic properties. Thus, it is necessary to have greater surveillance of the products so that consumers have access to quality dehydrated foods.

Development, survival, and reproduction of the psocid Liposcelis yunnaniensis (Psocoptera: Liposcelididae) at constant temperatures

We investigated the effects often constant temperatures (20.0, 22.5, 25.0, 27.5, 30.0, 32.5, 35.0, 37.5, 39.0, and 41.0 degrees C) on the development, survival, and reproduction of the psocid Liposcelis yunnaniensis Li & Li (Psocoptera: Liposcelididae). At 39.0 and 41.0 degrees C, none of individuals could develop successfully or reproduce. From 20 to 37.5 degrees C, the development period from egg to adult ranged from 64.3 d at 20 degrees C to 16.1 d at 35 degrees C. The lower developmental threshold for egg, nymph, and combined immature stages were estimated at 15.08, 15.13, and 14.77 degrees C, respectively. After emergence the females went through a preoviposition period that ranged from 18.5 d at 22.5 degrees C to 3.11 d at 35 degrees C, whereas it was 16.3 d at 20 degrees C. Liposcelis yunnaniensis produced most eggs at 35 degrees C and the fewest at 22.5 degrees C. The population reared at 35 degrees C had the highest intrinsic rate of increase, shorter mean generation time, and shortest population doubling time compared with other temperatures. According to Weibull frequency distribution, L. yunnaniensis reared at all the temperatures had type III survivorship curves (c < 1.0). Based on life-table parameter estimations, we suggest that optimum range of temperatures for this species is from 25 to 37.5 degrees C. These data give us useful information on population biology of L. yunnaniensis and can be used to better manage this species.