The genus Thraulus is widespread throughout much of the Eastern Hemisphere. Since Eaton established Thraulus in 1881, 62 species have, at one time or another, been placed in this genus. Thirty-eight of those species were eventually moved to other genera. Any comprehensive study of the remaining species, based on the published literature, is difficult as they were described by many authors, using different criteria, over a period of 142 years. The purpose of this study was to redescribe this genus, based on previously described species and nine new species, and to provide a format for future taxonomic and morphological studies of Thraulus. Redescriptions of most species were based on direct examination of external morphological characters. Descriptions or diagnoses of species, whose types were unavailable for study, were made using the original published description and additional information provided by authors of several of those species. The following species were studied: Thraulus amravati Vasanth, Subramanian & Selvakumar, 2022; T. bellus Eaton, 1881; T. bishopi Peters & Tsui, 1972; T. cuspidatus Vasanth, Subramanian & Selvakumar, 2022; T. demoulini Peters & Tsui, 1973; T. fasciatus (Kimmins, 1956); T. fatuus Kang & Yang, 1994; T. femoratus Li, Liu & Zhou, 2006; T. gopalani Grant & Sivaramakrishnan, 1985; T. jacobusi Isack, Srinivasan, Sivaruban & Barathy, 2022; T. macilentus Kang & Yang, 1994; T. malabarensis Vasanth, Subramanian & Selvakumar, 2022; T. mudumalaiensis Soman, 1991; T. plumeus Selvakumar, Vasanth & Subramanian, 2022; T. semicastaneus (Gillies, 1951); T. thiagarajani Balasubramanian & Muthukatturaja, 2019; T. thraker Jacob, 1988; T. torrentis (Gillies, 1964); T. turbinatus (Ulmer, 1909); T. umbrosus Kang & Yang, 1994; and T. vellimalaiensis Vasanth, Subramanian & Selvakumar, 2022. Nine new species of Thraulus are described: T. connubialis sp. nov., Malaysia; T. cursus sp. nov., Japan; T. eatoni sp. nov., Indonesia; T. ishiwatai sp. nov., Japan; T. madagasikarensis sp. nov., Madagascar; T. nihonensis sp. nov., Japan; T. opifer sp. nov., Australia; T. parentalis sp. nov., Malaysia; and T. petersorum sp. nov., Malaysia. Thraulus can be distinguished from all other genera of Leptophlebiidae by the following combination of characters: In the imagos, 1) upper portion of eyes oval-suboval, major axes diverge anteriorly; 2) vein MA fork of fore wings symmetrical; 3) vein MP fork of fore wings asymmetricala cross vein connects base of MP2 to MP1, MP fork closer to base of wing than Rs fork; 4) strongly oblique cross vein extends between veins R4+5 and MA1 just apical to fork of vein MA; 5) 2 cubital intercalary veins in fore wings; 6) costal projection on hind wings well-developed, bluntly rounded to acutely pointed; 7) claws dissimilarone blunt and pad-like, the other apically hooked; 8) penes long, relatively straight, narrow, parallel, usually contiguous mesally but not fused, apex may have lateral projections; 9) sternum 7 of female with posterior margin straight or shallowly concave or convex mesally; and 10) sternum 9 of females rounded apically. In addition, penile spines occur on most species. In the nymphs, 1) lateral margins of clypeus parallel; 2) width of labrum subequal to width of clypeus; 3) 2 dorsal rows of setae on labrum; 4) venter of labrum with 1 row of short stout setae on either side of midline near anterior margin, rows curve mesally; 5) hypopharynx with small, rounded, posterolateral projections on arms of superlingua; 6) large spine on posterolateral corners of terga 69, 79 or 89; 7) gills 17 dissimilar: gill 1 composed of 1 or 2 subulate lamellae or a dorsal subulate lamella and a ventral fimbriate oval lamella, and gills 27 composed of dorsal and ventral oval lamellae with fimbriate margins. Two species continue to be nomen dubiumT. siewertii (Weyenbergh, 1883) and T. vogleri (Weyenbergh, 1883). Thraulus grandis Gose, 1980 is considered nomen nudum. A review of published phylogenetic studies involving Thraulus is provided. With the species discussed in this paper, along with reports of additional new species to be described, Thraulus has the potential to be included among the more specious genera of Ephemeroptera.
A new species of the insect order Zoraptera, Zorotypus weiweii, is described and figured from Sabah, East Malaysia. The new species represents the second angel insect from Borneo. Z. caudelli Karny was also collected near the type locality of Z. weiweii. Methods of specimen collection and a brief note of angel insects in Malaysia were provided based on new materials and biological observations.
The climbing abilities of two bed bug species, Cimex lectularius L. and Cimex hemipterus (F.), were determined by evaluating their escape rates from smooth surface pitfall traps using four commercial bed bug monitors (Verifi Bed Bug Detector, ClimbUp Insect Interceptor, BlackOut Bed Bug Detector, and SenSci Volcano Bed Bug Detector). All detectors were used in the absence of lures or attractants. Unlike C. lectularius, adult C. hemipterus were able to escape from all traps. On the other hand, no or a low number nymphs of both species escaped, depending on the evaluated traps. Examination of the vertical friction force of adults of both species revealed a higher vertical friction force in C. hemipterus than in C. lectularius. Scanning electron microscope micrograph observation on the tibial pad of adult bed bugs of C. hemipterus showed the presence of a greater number of tenent hairs on the tibial pad than on that of adult C. lectularius. No tibial pad was found on the fourth and fifth instars of both species. Near the base of the hollow tenent hairs is a glandular epithelium that is better developed in adult C. hemipterus than in adult C. lectularius. This study highlights significant morphological differences between C. lectularius and C. hemipterus, which may have implications in the monitoring and management of bed bug infestations.
A new gall-inducing genus and species of felt scales (Hemiptera: Coccoidea: Eriococcidae) found on the leaves and twigs of Matayba guianensis (Sapindaceae) in Brazil is described: Bystracoccus Hodgson gen n. and B. mataybae Hodgson, Isaias & Oliveira sp. n. This is the first record of an eriococcid inducing leaf and stem galls on Sapindaceae and is only the second example of a member of the Eriococcidae to induce stem galls in which the insects diapause during the dry (winter) season. Only the adult female, second-instar female and crawler are known. The species overwinters as the first-instar nymph in pit galls on the twigs but spends the rest of the year associated with two-chambered galls on the leaves. It has recently become clear that South America has a rich felt-scale insect fauna many of which induce galls. It has proved very difficult to place this new genus in a family as it appears to fall between the Eriococcidae and Beesoniidae but is here placed in the eriococcids based on the similarity of the first-instar nymphs and the abundance of this family in the Neotropics. However, the dorsum of the abdomen of the mature adult female becomes heavily sclerotised, forming a round plug-like structure that completely fills the gall orifice. This structure shows remarkable morphological similarities to that of the beesoniid Danumococcus parashoreae Takagi & Hodgson found on Parashorea tomentella (Dipterocarpaceae) in Sabah, Malaysia, with which it is compared along with other eriococcid genera known from South America.