Protogyny is uncommon in caddisflies (Trichoptera) but does occur. I found protogyny in Lepidostoma satoi (Kobayashi, 1968) and L. complicatum (Kobayashi, 1968), while the congeneric L. itoae (Kumanski & Weaver, 1992) had a simultaneous emergence pattern of males and females. Dissection of the female internal reproductive organs revealed that the former two species had rather immature eggs, while the latter species had nearly mature eggs in the ovaries at emergence. Immature eggs needed 3 to 5 days to mature, but nearly mature eggs needed only 0 to 2 days. The mean longevity of females was 11.6 days in L. satoi, 10.4 days in L. complicatum, and 13.7 days in L. itoae. Male longevity in the former two species (4.6 days and 6.6 days, respectively) was less than the latter species (15.8 days). These results suggest that protogyny in L. satoi and L. complicatum is advantageous, allowing males to mate with mature females in a more timely manner, as the males can mate from the day of emergence. Protogyny at emergence may synchronize the mating period of the both sexes.

A new species of Themus (Haplothemus) Wittmer, 1973 is described and illustrated with aedeagus, T. (H.) imparipennis sp. nov. (China, Yunnan). In addition, T. (Themus) minimus Kopetz, 2010 is newly recorded from China, and the abdominal sternite VIII and genitalia of its previously unknown female are illustrated for the first time.

A new species of Myzomorphus Dejean, 1835 from Costa Rica is described, illustrated and included in the key previously revised by Galileo (1987).

The male of Microchironomus trisetifer (Hashimoto, 1981) is redescribed. The pupa of M. trisetifer and the larva and pupa of M. tabarui Sasa, 1987 are described for the first time based on material collected from southern China. Immature stages of M. tabarui deviate considerably from the previous generic concept. An emended generic diagnosis and keys to the known males and pupae are also provided.

Water hyacinth (Eichhornia crassipes (Martius) Solms-Laubach) is a non-native, invasive floating aquatic weed in the Sacramento San Joaquin Delta and associated river watersheds of northern California. Prior releases of biological control agents have not led to sustained control. The South American planthopper, Megamelus scutellaris Berg, 1883, permitted and released first in the southeastern U.S., was released at three sites in this region from 2011 to 2013, leading to establishment at one site in a pond off Willow Creek in Folsom in the American River watershed. Planthopper populations consisting of nymphs (two-thirds or more of total counts) peaked in late summer each year between 2013 and 2015, reaching densities of six to nine planthoppers per plant by 2015. Megamelus scutellaris dispersed 50 m per year from the point of release between 2013 and 2015 and, based on degree-day estimation, were capable of producing four generations per year at the Folsom site. Proportion live leaves per plant declined by 27% in the Folsom pond between 2012 and 2015. In 2015, plants in the release pond had 40% less live above-water biomass than plants 200 meters away in a canal, into which planthoppers had dispersed in 2014–2015. This early impact of the planthopper could, however, be obscured by inter-annual and within-site variability in plant growth. This study documents the first establishment of M. scutellaris on water hyacinth in the western U.S.

The green peach aphid, Myzus persicae (Sulzer, 1776) can cause significant economic losses in different crops in China. In the present study, we evaluated wing shape and size variation among biotypes from tobacco, Nicotiana spp. (Solanaceae), cabbage, Brassica oleracea L. (Brassicaceae), and peach, Prunus persica (L.) Batsch (Rosaceae), and tested whether specimens could be distinguished at the population level. Fifteen landmarks were measured on the wings and used to generate geometric morphometric size and shape data from 137 specimens of M. persicae from three host plants: tobacco, cabbage and peach. Analysis of wing size showed that the peach biotype had the smallest wing centroid size. A one-way ANOVA of centroid size showed significant inter- and intra-populational differences. A Tukey post-hoc test revealed that the wing centroid size of the peach population was significantly smaller than that of either the tobacco or cabbage population. DFA cross-validation test showed that all tobacco biotype specimens were correctly classified, while 83% and 84.1% of peach and cabbage biotype specimens, respectively, were correctly classified. These results suggest that geometric morphometrics based on wing shape has potential for distinguishing M. persicae biotypes.