Bagrada hilaris (Burmeister) 213
progeny. The egg laying behavior of Bagrada hilaris appears to be extremely unusual for a stink bug
and has been described in detail by Taylor et al. (2014). The majority of stink bug species deposit their
eggs on host plants in clusters or distinct rows (Esselbaugh 1956, Hinton 1981, McPherson 1982). In
the Old World, a few species have been reported to deposit eggs individually or in small clusters on the
soil surface or on detritus (Puchkova 1961). Reports on egg laying for B. hilaris have been variable.
Eggs have been reported to be laid singly or in small clusters on leaves or stems of its host, on the soil
surface or detritus, in cracks in the soil (Hutson 1935, Pruthi 1946, Rakshpal 1949, Batra 1958, Ghosal
et al. 2006, Arakelian 2010, Halbert and Eger 2010, Perring et al. 2013, Reed et al. 2013b), on artificial
materials such as shade cloth or row cover (Darcy A. Reed, personal communication), or beneath the
soil surface (Samuel 1942). However, Taylor et al. (2014), in documenting the ovipositional behavior
of B. hilaris, found that the female actively buries each egg, the first known report of this behavior for
a stink bug. Upon finding a suitable ovipositional site, the female anchors herself (positioning phase)
to the substrate and pushes her abdomen beneath the soil surface. She then stops moving (stationary
phase) as an egg apparently passes through her oviduct. Following, she then begins pivoting her abdo-
men back and forth and then deposits the egg in the soil (egg deposition phase). Finally, she withdraws
her abdomen from the soil (abdomen withdrawal phase) and actively covers the egg with soil using her
hind legs (covering phase).
3.4.2 Host Plants
Bagrada hilaris is a polyphagous insect that is known to utilize 96 hosts in 25 families (Table 3.1).
Although most of its hosts are in the family Brassicaceae (n = 30), it also feeds on multiple species in the
Asteraceae (n = 8), Fabaceae (n = 11), and Poaceae (n = 16). Because many of its brassicaceous hosts are
agricultural plants, it is in this group where the majority of economic damage occurs. Recent studies by
Huang et al. (2014b) demonstrated preference of B. hilaris for certain brassicaceous plants over others.
They found that it was most attracted to radish, Raphanus sativus L., followed by red cabbage, Brassica
oleracea var. capitata, sweet alyssum Lobularia maritima L. (Desv.), arugula, Eruca sativa Mill., and
broccoli, B. oleracea var. italica Plenck. Additional work showed a preference for feeding on the younger
growth of Brassica sp. seedlings. Feeding significantly reduced leaf area, dry weight, and chlorophyll
content of all hosts fed upon by this bug (Huang et al. 2014a).
Reed et al. (2013b), in a series of greenhouse studies, showed a number of plants were not utilized
as hosts by Bagrada hilaris. These plants were distributed across several plant families and included
the following: Amaranthaceae – Chenopodium sp., Spinacia oleracea L.; Apiaceae – Coriandrum
sativum L, Senecio vulgaris L., Lactuca sativa L., Sonchus sp.; Cucurbitaceae – Cucumis melo L.,
Cucumis sativus L, Cucurbita foetidissima Kunth, Cucurbita pepo L.; Fabaceae – Lotus corniculatus
L., Vicia faba L., Glycine max (L.) Merrill; and Solanaceae – Capsicum annuum L., Solanum nigrum
L., S. lycopersicum L., Nicotiana glauca Graham. Despite their findings, some of these plants (e.g.,
C. melo, C. annuum, and S. lycopersicum) have been reported as hosts by other authors (see Table
3.1). Although these results show that B. hilaris will infest a wide range of hosts, and even cause
economic damage, we believe these situations are due to the bugs being in close proximity to more
preferred brassicaceous hosts. When the non-brassica hosts Parthenium hysterophorus, Pluchea lan-
ceolata, Ziziphus zuzuba, Chenopodium album, and Calotropis procera were grown near mustard,
B. hilaris was found in high numbers. However, after the mustard was harvested, bug populations
declined (Patidar et al. 2013b).
These non-brassicaceous plants also may be “bridging hosts,” used by Bagrada hilaris to bridge the
gap between the end of one season of a brassicaceous crop and the beginning of the next. This was
the case for B. hilaris infestations in wheat, invading only after nearby crucifers had been harvested
(Cheema et al. 1973). B. hilaris also has been observed feeding on corn as a “bridge” between spring-
harvested and fall-planted cole crops in the southwestern United States. Dissections of insects collected
from the corn revealed depleted fat bodies, an indication that the bugs were not obtaining adequate nutri-
ents from that plant (Thomas M. Perring and Darcy A. Reed, personal observations).