Southern Green Shieldbug Nezera viridula, new to Essex and a
shield bug to look out for in the county
Peter Harvey 32 Lodge Lane, Grays, Essex RM16 2YP
In summer 2003 three breeding populations of the Southern Green Shieldbug Nezera
viridula were discovered outdoors in London (Barclay 2004, Shardlow & Taylor 2004),
the first time the species had been found in Britain as anything other than a casual
occurrence.
The nymphs of N. viridula are distinctive, the fifth instars having 4 rows of white markings
on the greenish abdomen, with red markings on the edge of the pronotum, as well as a
red spot on the margin of every abdominal segment (see Plate 8). The earlier instars are
blackish brown, from at least the second instar onwards with four large white spots on
each side of the abdomen. Adults most closely resemble our native Green Shieldbug
Palomina prasina (see Plate 6), but N. viridula is said to be larger (not something I have
noticed in the single adult I reared through, prompting this report), and has a clear
membrane, the base of the abdomen appearing green rather than brown as in Palomena.
The base of the scutellum has a row of 3-5 small white spots with a small black spot at
each corner (see Plate 7). Apparently in some individuals the head and front margin of
the pronotum can be cream-coloured.
N. viridula has been recorded feeding on Wayfaring tree Viburnham lantana at Camley
Street Natural Park near Kings Cross Station (Shardlow & Taylor 2004) and tomato
plants in the Queens Park area of London (Barclay op. cit.), but it has also been found on
Golden Rod, Hemp Agrimony and other plants at Camley Street and causes crop damage
in some warmer countries (Brooke 2004) on a range of crops including tomatoes, pecans,
potatoes, cotton, grapes, beans, cabbage, citrus, cucurbits, cannabis, macadamia nuts,
mango, orchids, peppers, soybeans and watercress (Shardlow & Taylor op. cit.).
On 21 Oct 2003 I collected a 5th instar nymph at abrownfield site in Stratford (TQ377841),
which has probably been destroyed as part of developments in preparation for the 2012
Olympics. I remember noticing its striking appearance at the time, but did not record
whether I had swept it from herbage or beaten it from scrub at the site. Peter Kirby
subsequently identified the shield bug along with other bug and plant hopper material I
sent him at the time. Then on 12th August 2008 I swept a 5th instar nymph from herbage
beside an old track at a post industrial site near Stanford le Hope. Although I kept it
alive in captivity in the hope of rearing it through, it died after a couple of weeks.
However on 23rd August at the same site, and in exactly the same area, I swept two more
5th instar nymphs, one of which I again kept alive in captivity. This one moulted and
matured into an adult on 27th August. A further 5th instar nymph was swept, again from
the same area, on 8th September.
Clearly this shield bug is likely to turn up elsewhere in the Thames Gateway region and
could well appear elsewhere in Essex.
20 Essex Field Club Newsletter No. 59, May 2009