Mombasinia superba (Photos 1 to 19). Note: I numbered the photos from 1 to 19 (on the lower right hand side of each photo), but the reference to these numbers in my text below do not follow this chronological order.
Background
The species is described in this publication:
De Lotto, G. 1964. A new species of Mombasinia (Hom.: Pseudococcidae) from South Africa. Proceedings of the Linnaean Society of London 175(2): 135-136. I cannot access it – is someone maybe lucky to have a copy that they can share – thanks (@traianbertau, you are good at finding obscure and old publications, can you kindly help).
According to: "Millar, I. 2002. Mealybug genera (Hemiptera: Pseudococcidae) of South Africa: Identification and review. African Entomology 10(2): 185-233", (of which I have a copy), there are only two species in the genus, with M. superba occurring in South Africa, and the other one occurring in Kenya. He does not mention the other species, and iNaturalist only lists M. superba.
The only host plants recorded for the genus are Flacourtia indica and Scolopia zeyheri. I have posted pictures of the host plant on which I found the mealybugs here:
https://www.inaturalist.org/observations/230669447
My observations
Massive “colonies” may occur on the undersides of leaves. I did not do a study to determine their life cycle, nor their occurrence over a long period. During winter the leaves of the trees start to dry out and curl, showing their undersides, and in the process revealing the mealybugs on infested trees. Small trees may be infested so badly that they appear white from a distance in winter (16; 17). The dorsal parts of lower leaves, as well as some stems and twigs, and the area below the trees, were typically covered in a black sooty mould (17). Fallen, dry leaves retain the snow white colour of the mealybug scales, below the trees (17), and are very conspicuous, even revealing the position of the smallest inconspicuous trees growing low between the grasses. I did not investigate whether the mealybugs inflict any damage to the leaves or trees. Apart from the wax structures on the bodies of the mealybugs, it seems that they produce extra loose wax plates, roughly in the shape of “bent” rectangles - visible on some photos (11; 12; 13;) that they use to cover the entire colony on a leaf (eggs, nymphs and adults). Photo 6 may give an indication of the location on the mealybug body from where these wax plates are produced (in pairs from the sides). These wax plates are kept in place (as a roof) above the colony (14) by sticky filaments (maybe honeydew); they are not firmly fixed, but impossible to remove with forceps or micro brushes – if you try, everything comes off as a sticky entangled mess (18). You cannot blow off the wax filaments, they just “flutter”, but stay in place.
Eggs: They are laid singularly, but may occur in groups, hidden under the wax layers, but not in egg sacks (15, black arrow). They are very small, I think approx. 0,1 mm. I found them in early winter, but do not know whether they start to appear earlier.
Nymphs: They occur with the adults under the wax layers, even in winter (July in Pretoria) (3, 5, 11, 12, 13). They are approx. 0,5 to 0,75 mm in length. The smallest nymphs are orange/yellow, and some portions of wax extensions are visible on some. Nymphs were seen walking on stems of trees in the winter, presumably looking for hiding/overwintering places to wait the cold months out and for new growth to appear in spring.
Adult females: They are approx. 1,2 mm in length, excluding the long wax extensions. The wax extensions are very characteristic: four pairs of long thin extensions anteriorly, and two similar pairs posteriorly (clearly visible in 8 and 9). Sometimes these extensions may be twice the length of the body (7), but mostly breaks off easily and are mostly shorter. There is an additional shorter tail visible on some individuals (5). There are also spiralling wax disks on the dorsal abdomen and thorax. It looks like three pairs, but it is not always clear. The two anterior spirals may be extended with up to five curls (9). The other spirals are broader and flatter.
Adult males: During winter I only found a few males, maybe more are produced earlier. They are winged, and just over 1 mm in length (19).
Disclaimer: The above description is by myself, and not on a professional taxonomic standard (I am not a taxonomist). I could not find any publication that gave descriptions of the live (alive) stages, if anybody find some, kindly share so that we can compare my observations/descriptions with those of other observers, and make corrections if needed.
The submission of the tree on which the mealybugs were found can be found here: https://www.inaturalist.org/observations/230669447.
Eristalinis quinquelineatus suggested by Traian Bertau (Insects Only - Southern Africa)
UPDATE
With reference to this submission:
https://www.inaturalist.org/observations/155565115
This is the same male as in the observation cited above.
The male was identified by Prof Ansie Dippenaar as a Trichonephila species.
The observation confirms that a Trichonephila male was observed with his "genitals" inside the genitals of an Argiope female.
The following may now be applicable:
My question is whether inter-genus matings in spiders have been observed before.
Thank you if you can shed some light on my observation - appreciated.
@hrodulf
@razorspider
@geologyistheway
Loxosxeles sp.
Leaf minrs, found two on the same plant
? Pretended to be dead when I picked it up. About 2mm.
Very shy of the camera, does not stay still when approached.
Busy inside a very small, looks like a cocoon. Found on leaves of a Vachellia (thorn tree)